[clang] Optimize -Wunsafe-buffer-usage. (PR #124554)

[Ilya Biryukov via cfe-commits]

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@@ -79,21 +81,39 @@ static std::string getDREAncestorString(const DeclRefExpr *DRE,
 } // namespace
 #endif /* NDEBUG */
 
-namespace clang::ast_matchers {
+class CustomMatcher {
+public:
+  virtual bool matches(const DynTypedNode &DynNode, ASTContext &Ctx,
+                       const UnsafeBufferUsageHandler &Handler) = 0;
+  virtual ~CustomMatcher() = default;
+};
+
+struct MatchResult {
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ilya-biryukov wrote:

NIT: you likely want this to be `class`. (because it has a member function)
Alternatively, make this a `struct` and have a convenience function?

https://github.com/llvm/llvm-project/pull/124554